A cross-site scripting (XSS) vulnerability was recently revealed in the WordPress caching plugin, WP Super Cache.

What Does The WP Super Cache Plugin Do?

WP Super Cache converts dynamic WordPress pages into static HTML.  This creates pages that are quicker to serve to visitors than a database-generated page. Great for high traffic sites, WP Super Cache’s popularity has garnered over a million downloads.

Details Of The XSS Vulnerability

A cookie-based XSS vulnerability was found using the function, wp_cache_get_cookies_values().  This function is called to append a unique ID, or key, that WP Super Cache uses to determine which cached pages to serve.

Given this, an attacker could request a page with the site’s cookie edited to include an XSS exploit.   Super Cache generates the page appending the malicious cookie payload, and WP Super Cache’s cached file list page is served up exploit and all, stealing the admin’s cookies or performing other mayhem.

Impact On WordPress Websites

Versions of WP Super Cache below 1.4.4 contain the XSS vulnerability and should be patched to the latest version as soon as possible. Back up your site’s database and files and then run the update in the admin panel, or download the latest version from WP Super Cache’s official page. Owners with a vulnerable version of the WP Super Cache plugin on their site are also urged to change the WordPress admin password.

Or, better yet, obviate the need for WP Super Cache by deploying the SiteLock TrueSpeed CDN and TrueShield WAF. The unparalleled coverage of the SiteLock global CDN intelligently serves your most elaborate WordPress site pages in the quickest, most efficient manner to all visitors, regardless of geographic location. (A cached page could still be slow if it’s served to a visitor on the other side of the world.)

Plus, the integrated TrueShield web application firewall eliminates such attacks altogether, so you’re protected from the next, inevitable, WordPress plugin vulnerability before it even happens.

SiteLock TrueSpeed CDN and TrueShield web application firewall are included in many of our website protection packages.  Visit our site to learn more about the features included in each service plan.